The world of video and television is in the middle of a move from the analog era to the digital era. All over the world, broadcasters are changing their infrastructure to support both analog and digital services, until the digital revolution is complete.
A major issue for multiple service operators (MSO's) is gathering digital transmissions from several sources, such as satellite channels, encoders and video servers, and binding them to new digital streams at a constant bit-rate. The action of selecting programs from existing bunches of programs, and reorganizing them into new bunches of programs, is called re-multiplexing.
A typical digital video program needs a bandwidth of about 4 Megabits per second. MSO's promise their customers to provide a variety of interactive services, such as video on demand and time-shifted TV. For re-multiplexers to provide these services concurrently to a large number of users requires a huge aggregated bandwidth of many Gigabits per second and powerful processors.
Current re-multiplexers usually use standard processors, such as general-purpose processors and digital signal processors (DSP's), to provide the functionality of re-routing digital video packets to a defined output port. These processors lack the ability to effectively handle the amounts of bandwidth required for the interactive services. Numerous re-multiplexers would be needed in a digital head-end for this purpose, causing both high expenses and complicated management.
Several techniques are already in use for several years in fields such as Telecom, to efficiently handle routing of large amounts of data. One of these techniques is usage of several processors working in parallel for the same application, thereby shortening processing time linearly. Another technique is called “cut-through,” based on the concept of a quick decision on how to handle a packet according to a header, for example, only. Since there is no need to wait for the arrival of the full packet before the decision, waiting time is saved and the processing efficiency is improved. U.S. Pat. No. 6,438,145 to Movshovich et al, describes a “Transport packet distribution system and method using local header.” Local information is generated and included in a header for each transport packet, which is used for identification and distribution.
These techniques are not yet adopted by the world of digital video, and using them may provide the tools to efficiently handle the growing demand of routing video packets to their destination.
Therefore, it would be advantageous to provide a re-multiplexer wherein the digital video packets can be processed at gigabit bandwidth rates.